Traffic controlling system for railroads



Dec. 1, 1936. c. s. BUSHNELL TRAFFIC CONTROLLING SYSTEM FOR RAIL-ROADS Filed Jan. 9, 1932 C ow W5?! Patented Dec. 1, 1936 TRAFFIC CONTROLLINGUSIISTEM non RAILROADS Charles S. Bushnell, Rochester,-N. Y., assignor to General Railway Signal Company, Rochester,

Application January 9,1932, Serial No. 585,726

13 Claims. (01. 246-242) This invention relates to traffic controlling systems for railroads, and more particularly perusually associated therewith so as to prevent the 010 tains to the remote control of railroad track switches. In interlockingsystems and other similar systems where railroad track switches are controlled by an operator from a central point-suitable automatic signaling and interlocking means are unsafe operation of the track switches. I Whenever trafiic conditions are proper for the opera- .tion of a track switch, it is desirable that suittion to the other.

he originally intended to set up, will find it necessary to reverse the operation of the track switch in mid stroke; or, the-track switch may become stalled in mid stroke and the operator, desiring to return it to its original position, must reverse the operation of the switch machine.

In governing switch machines for the opera- H tion of the track switches, means must be provided for opening the operating circuit at the end of a particular operation so as to bring the switch'machine motor to rest.

inertia of the various parts being operated, there is sometimes considerable overrun after the operating circuits of the motor have been opened.' It is, therefore, desirable that'somemeans may be provided for limiting the amount of overrun;v

the other, and reversed in mid stroke, when desiredf The invention also contemplates arranging the control circuits in such a manner that filed May 12, 1931.,

tures of the present invention will be in part obvious from the accompanying drawing, and inpart pointed out as the description thereof progresses.

Indescribing the present invention, reference;

- will be made to the accompanying drawing which However, due to the momentum of the motor armature, and the illustrates in a diagrammatic manner the devices and circuits chosen as one embodiment of the invention, as adapted for. the controlof a single railroad track switch.

With reference to the accompanying drawing,

arailroad track switch TS is illustrated as being .operatedby a suitable switch machine SM, such for example as disclosed in the patent to W. K.

Howe Patent No. 1,466,903, dated September 4, 1923. This switch machine is provided with a motor having the usual armature A and field winding F for driving the switch machine mechable control-be provided sov that the operator may operate the track switch fromone extreme posi- Sometimes it may occur that the operator, desiring to changethe route which anism. g

1 Included within the switch machine and operated thereby are suitable switch machine contacts SMC which assume normal, mid stroke and reverse-positions, iorin part governing the operation of the motor.- Thesecontacts include fournormal pairs of fixed contacts and four reverse pairs of fixed contacts, together-with certain movable contacts which assume normal, mid stroke and reverse positions, and these movable contacts, when in certain of 7 these positions, make contact between their respectivepairs of fixed contacts, as more specifically pointed out hereinafter, j

Associated with the switch machine and either included in its housing or located adjacent thereto, is a suitable control relayfCR of the twoposition polar type. This relay is responsive to the application of current of opposite polarities to its terminals for operating its polar contacts to oppositev positions. Preferably associated with jfthej. polar contacts of "this relayare suitable .meansior holding the contactsin their last op, Ierated position-irrespective of the deenergization of thewindings of therelay, which means may be a'suitable magnetic stick arrangement or a suitable mechanical toggle device. Such a relay has been disclosed forfexample in the pending application of J. F. Merkel, Ser. No; 536,917,

wAlthough the particular embodiment chosen governed by the control relay. CR and the switch machine contacts SMC, it isito be understood I that 'such'control may be repeated bysuitable contactors having associated therewith magnetic blow-out means for are suppression andthelike. gAlso, suitable overload means may be provided inconnction with the operating circuits, in such a manner that it;is efiective to open the operat circu nig hec st pe ates h ev of an overload, but permits theclos'ure' or) the op;

posite operating circuit so as to enable the track switch to be returned to its original position, all of which is preferably provided in connection with such a remote control system as contemplated by the present invention but for the sake of simplicity has been omitted.

Associated with the track switch TS are provided the usual detector track section and signals for governing tramc thereover all in accordance with the usual practices.

In the tower a suitable switch machine lever SML is provided for governing the polarities applied to the control relay CR for operating its contacts to opposite extreme positions. Although this switch machinelever SML is shown as a simple free lever, it is to be understood that it preferably has associated therewith. either suitable mechanical interlocking, or suitable electrical interlocking providing the usual safeguards for the operation of railroad track switches.

Suitable sources of electrical energy are provided both in the operators tower and at the switch as illustrated in this case by batteries BT and B respectively.

It is believed that the nature of the invention, its advantages and characteristic features can be best understood with further description being set forth fromthe standpoint of operation.

' Operation With the control lever SML in a normal position as illustrated, the control relay CR is energized by a circuit from the positive terminal of battery BT, through wire 5, contact 6 of lever SML in a normal position, line wire 1, windings of control relay CR, line wire 8, contact 9 of lever SML in a normal position, to the negative terminal of battery ET. The current which flows in this circuit causes the contacts of the control relay CR to be actuated to left hand positions, as

illustrated. n

Assuming that the automatic signalling associated with the track switch TS and the switch machine control lever SML is in condition to allow the safe operation of the track switch, we may assume that the operator moves thelever SML to the reverse position thereby reversing the polarity of the current energizing the control relay CR and actuating its contacts to right hand positions for causing thereverse operation of the switch machine; This reverse control circuit is closed fromthe positive terminal of battery BT,

through wire IE1, contact 9 of lever SML in a re-' jwire 23, polar contact 24 of control relay CR in a right hand position, ,wires 25 and 26, contacts 21-28, wires 29 and 30, field winding F, wires 3| and 32, to the negative terminal of battery 2B.

The current which flows in this reverse operating circuit causes the motor armature A to revolve in a reverse direction for unlocking the track switch TS and operating it from its normalposition to the reverse position and again looking it.

During such reverse operation of the track switch TS and while it is unlocked, the movable switch machine contacts SMC are operated to mid stroke positions opening contacts 35-36 and 31-38, but closing contacts 39-40 and 4|-42. Thus, should the operator desire to interrupt the reverse operation of the switch machine in mid stroke and cause the track switch to be returned to its normal position, he would merely return the control lever SML to the normal position thereby reversing the polarity of the current applied to the control relay CR and operating the contacts 2| and 24 to normal positions.

In the event of such operation, a normal operating circuit is completed from the positive terminal of battery B, through wires I and 43, contacts 39-40, wires 44 and 45, polar contact 24 of control relay CR in a left hand position, wire'23, armature A, wire 22, polar contact 2| of control relay CR in a, left hand position, wires 46 and 41, contacts 4|-42, wires 48, 49 and 30, field winding F, wires 3| and 32, to the negative terminal of battery B. The current which fiows in this normal operating circuit causes the motor armature to operate in a normal direction for returning the track switch to its normal locked position.

However, assuming that the switch machine SM continues its reverse operation by reason of the switch machine control lever SML being left in its reverse position, the movable switch machine contacts are operated to reverse positions when the track switch TS has been operate-d to a reverse position and locked. Such operation opens the reverse operating circuit of the armature A and field winding F at contacts |1-|8 and 21-28; but closes a snubbing circuit for the switch machine motor from the lower terminal of the field winding F, through wires 3|, 50 and 5|, contacts 52-33, wires 53 and 25, polar contact 24 of control relay CR in a right hand position, wire 23, armature A, wire 22, polar contact 2| of control relay CR in a right hand position, wires 20 and 54, contacts 55-36, wires 56, 49 and 30, field winding F, back to wire 3|. Inasmuch as this snubbing circuit, closed after the reverse I operating circuit is opened, causes the reversal of the armature A with respect to the field winding F, the motor then acts as a generator causing a dynamic current to be produced, thereby dissipating the momentum stored inv the armature. This quickly brings the armature and the operating mechanism to a condition of rest.

In a similar manner to that described, the track switch TS may be operated from a reverse position to a normal position through the normal operating circuit already pointed out above. When such normal operation of the switch machine is completed, a normal snubbing circuit is closed from the lower terminal of field winding F, through wires 3|, and 51, switch machine contacts 31-38, wires 58 and 46, polar contact 2| of control relay CR in a left hand position, wire 22, armature winding A, wire 23, polar contact 24 of control relay CR in a left hand position, wires 45 and 59, contacts 35-36, wires 60 and 30, field winding F, back to the wire 3|. It is noted, that this circuit also reverses the armature with respect to the normal operating circuit so that the motor acts as a generator causing the dynamic current to flow and quickly bringing the motor armature and the switch machine operating mechanism to a condition of rest.

It will be noted that a snubbing circuit is closed with the switch in either extreme position, which thereby serves to prevent the response of the switch machine to the application of unauthorized currents.

A switch machine control circuit has thus been provided in accordance with the present invenof the armature at the end of each operation causes the switch machine mechanism to be quickly brought to rest.

Having thus described a switch machine control circuit as one embodiment of the present invention, it is desired to be understood that this form is selected to facilitate in the disclosure of the invention rather than .to limit the number of forms which it may assume; and, it is to be further understood that various modifications, adaptations and alterations may be applied to the specific form shown to meet the requirements of practice, without in any manner departing from the spirit or scope of the present invention except as limited by the appended claims.

What I claim is:-

1. In combination, an electric motor, motor contacts capable of assuming normal, reverse and mid-operation positions, a device having control contacts capable of assuming only normal and reverse circuit closing positions, normal and reverse snubbing circuits closed when said motor contacts are operated into correspondence with said control contacts in normal and reverse positions respectively, a normal operating circuit for said motor closed with said control cont-acts in normal positions out of correspondence with said motor contacts in reverse or mid-operation positions, and a reverse operating circuit for said motor closed with said control contacts in reverse positions out of correspondence with said motor contacts in normal or mid-operation positions,

whereby said motor may be operated in normal or reverse directions and reversed at any time during operation, and whereby said niotor is dynamically snubbed at the end of each operation.

2. In a trafiic controlling system for railroads, a railroad track switch, a switch machine for operating said track switch, switch machine contacts capable of assuming normal, reverse and mid-stroke positions in correspondence with said track switch, a manually operable device having control contacts capable of assuming only normal and reverse circuit closing positions, a normal operating circuit for said switch machine closed with said control contacts in normal positions out of correspondence with said switch machine contacts in reverse or mid-stroke positions, a reverse operating circuit for said switch machine close-d with said control contacts in reverse positions out of correspondence with said switch machine contacts in normal or mid-stroke positions, and normal and reverse snubbing circuits closed when said switch machine contacts are operated into correspondence with said control'contacts in normal or reverse positions respectively,

whereby said switch machine may be operated to normal or reverse positions, "whereby said switch machine may be reversed in mid-stroke, and whereby said switch machine is dynamically snubbed at the end of each operation.

3. In a control circuit for switch machines of the electric motor dynamic braking type, the combination with a switch machine having a normal, a reverse and a mid-stroke position, a

manually controlled device having only a normal and a reverse circuit closing position, two operating circuits for said switch machine closed. respectively when said device assumes the normal and the reverse position providing the switch xmachine is either out of correspondence with said device or assumes the mid-stroke position and including only contacts operated only by said device and contacts operated only by said switch machine, and a snubbing circuit closed only when said device and said switch machine assume corresponding positions and including contacts operated only by said device and contacts operated only by said switch machine. I

4. In a control circuit for switch machines of the electric motor dynamic braking type; the combination with .an electrically operatedswitch machine including an electric motor of the single field type, and having a normal, a reverse and a mid-stroke position; a manually controlled device having, only a normal and a reverse circuit closing position; two operating circuits for said switch machine closed respectively when said device assumes the normal and the reverse position providing the switch machine is either out;

snubbing circuit closed only when said deviceand said switch machine assume corresponding positions, and including only contacts operated only by said device and contacts operated only by said switch machine.

5. In a control circuit for switch machines of the electric motor dynamic braking type; the combination with an electrically operated switch machine including an electric motor of the single field type, and having a normal, a reverse .and a mid-stroke position; a manually controlled device having only a normal and a reverse circuit closing position; a normal operating circuit for said switch machine including only contacts operable only by said switch machine and closed when and only when said switch machine assumes either a reverse or a mid-stroke position, and contacts of said device closed when and only when said device assumes the normal position;

and a normal snubbing circuit for said switch field type, and having a normal, a reverse and a mid-stroke position; a manually controlled device having only a normal and a reverse circuit f closing position; contacts operated only by said device which may assume extreme normal or reverse positions; contacts operated only mechanica'lly and by said switch machine, and which may assume extreme normal or reverse or a midstroke position only if the switch machine assumes a corresponding position; operating cir-. cuits for said switch machine closed only when the contacts of said device and the contacts of said switch machine assume extremeout of correspondence positions or when thecontacts of said device assume an extreme position, and the contacts of said switch machine assume the midstroke position; and dynamic braking circuits closed only if the contacts of said device and the contacts of said switch machine assume corresponding positions. i. I

'7. In a switch machine having a reversible motor, a control device having contacts closed respectively only when said deviceassumes an extreme normal or an extreme reverse position, operating circuits for said switch machine including contacts operated only mechanically and only by said motor and contacts operated only by said control device, one of said operating circuits being closed at all times except when said-switch machine assumes the same extreme position as that assumed by said control device, and dynamic braking circuits including contacts operable only by said control device and contacts operated only mechanically and only by said motor, said braking circuits being closed only when said switch machine assumes the same extreme position as that assumed by said control device, said contacts operated by said switch machine being slightly break-before-make.

8. A switch machine and control means therefor comprising in combination, a switch machine, a manually controlled two position relay having normal and reverse contacts, a first set of contacts closed only if said switch machine assumes the full normal position, a second set'of contacts closed only if said switch machine assumes the full reverse position, a third set of contacts closed only if the switch machine assumes either a full normal or a mid-stroke position, a fourth set of contacts closed only if said switch machine assumes either a full-reverse or a mid-stroke position, a circuit for operating said switch machine from the normal to the reverse position including one of said third contacts and one of the reverse contacts of said relay, circuits for operating the switch machine in either direction when said switch machine assmnes a mid-stroke position including either one of said third contacts and one of said reverse contacts or one of said fourth contacts and one of said normal contacts, and a reverse snubbing circuit including one of said reverse contacts and one of said second contacts.

9. A switch machine and control means therefor comprising in combination, a switch machine, a manually controlled two position relay having normal and reverse contacts, a first set of contacts closed only if said switch machine assumes the full normal position, a second set of contacts closed only if said switch machine assumes the full reverse position, a third set of contacts closed only if the switch machine assumes either a full normal or a mid-stroke position, a fourthset of contacts closed only if said switch machine assumes either a full-reverse or a mid-stroke position, a circuit for operating said switch machine from the normal to the reverse position including one of said third contacts and one of the reverse contacts of said relay, circuits for operating the switch machine in either direction when said switch machine assumes a mid-stroke position including either one of said third contacts and one of said reverse contacts or one of said fourth contacts and one of said normal contacts, a reverse snubbing circuit including one of said reversecontacts and one of said second contacts, a circuit for operating said switch machine from the reverse to the normal position including one of said fourth contactsand one of said normal contacts, and a normal snubbing circuit including one of said normal contacts and one of said first contacts.

10. A switch machine and control means therefor comprising in combination, a switch machine having an armature and a single field winding, a

manually controlled two-position relay having normal and reverse contacts, a first set of confull-reverse position, a third set of contacts closed only if the switch machine assumes either a fullnormal or a mid-stroke position, a fourth set of contacts closed only if said switch machine assumes either a full-reverse or a mid-stroke position, circuits including said armature and field winding in series for operating the switch machine in opposite directions when said switch machine assumes a mid-stroke position including one of said third contacts and one of said reverse contacts or including said fourth contacts and one of said normal contacts, only one or the other of these circuits being closable when the switch machine assumes respectively a full-normal or full-reverse position, and snubbing circuits including said armature and field winding in series and including one of said normal contacts and one of said first contacts or including one of said reverse contacts and one of said second contacts.

11. A switch machine and control means there for comprising in combination, a switch machine having an armature and a single field winding, a manually controlled two-position relay having normal and reverse contacts closed respectively with the relay in the normal and reverse position, a first set of contacts closed only if said switch machine assumes the full-normal position, a second set of contacts closed only if said switch machine assumes the full-reverse position, a third set of contacts closed only if the switch machine assumes either a full-normal or a mid-stroke position, a fourth set of contacts closed only if said switch machine assumes either a full-reverse or a mid-stroke position, operating circuits for operating the switch machine in either direction when said switch machine assumes a mid-stroke position including one of said third contacts and one of said reverse contacts or including one of said fourth contacts and one of said normal contacts, only one of said circuits being closable when said switch machine assumes the normal position and only the other circuit being closable when said switch machine assumes the reverse position, and a snubbing circuit closed when said switch machine has completed its stroke in response to closure of one of said operating circuits, said snubbing circuit including one of said reverse contacts and one of said second contacts or including one of said normal contacts and one of said first contacts.

12. In a switch machine having a reversible motor for operating it to a normal or to a reverse position and having four sets of contacts operable only by the motor thereof, the first set of contacts being closed only when the switch machine assumes the full-normal position, the second set of contacts being closed only if the switch machine assumes the full-reverse position, the third set of contacts being open only when the switch machine assumes the fullreverse position and the fourth set of contacts being open only if the switch machine assumes the full-normal position; of a manually controlled device having a control contact and a snubbing contact each contact of which may as sume a normal or a reverse position; a normal operating circuit for said motor closed only when said fourth set of contacts is closed and said control contacts assume the normal position; a reverse operating circuit for said motor closed only if said third set of contacts is closed and said control contacts assume the reverse position; and a snubbing circuit closed only if said switch machine and said snubbing contact assume corresponding normal or reverse positions.

13. In a switch machine having a reversible series motor for operating it to a normal or to a reverse position with the field and armature connected respectively in normal and reverse relation and having four sets of contacts operable only by the motor thereof, the first set of contacts being closed only when the switch machine assumes the full-normal position, the second set of contacts being closed only if the switch machine assumes the full-reverse position, the third set of contacts being open only when the switch machine assumes the full-reverse position and the fourth set of contacts being open only if the switch machine assumes the full-normal position; of a manually controlled device having a control contact and a snubbing contact each contact of which may assume a normal or a reverse position; a normal operating circuit for said motor including said field and armature in normal series relation closed only when said fourth set of contacts is closed and said control contacts assume the normal position; a reverse operating circuit for said motor including said field and armature in reverse series relation closed only if said third set of contacts is closed and said control contacts assume the reverse position; and a snubbing circuit closed only if said switch machine and said snubbing contact assume corresponding normal or reverse positions.

CHARLES S. BUSHNELL. 

